booting 4.3-reno without a tape drive

Mon Nov 23 08:15:50 AEST 1998

Michael Sokolov wrote:

>   How soon will this happen? I'm all ready to go, but unfortunately
>hardware problems are holding me back. I have solved the KA650 problem I
>was having, but now I'm stuck because neither of the two TQK50 boards I
>have works. (The drive SEEMS to work, though.) Thus the sooner I find a
>working TQK50 board (or, alternatively, a working TK70/TQK70 pair), the
>sooner will I make 4.3BSD-Quasijarus1.

For a quick work-around to make a bootable 4.3 miniroot without a
tape drive, Michael, you might consider the following (similar
tricks will work on NetBSD distributions too):


  Microvax II
  Honest-to-goodness DEC disk or *fully* compatible 3rd-party disk.
    *Fully* compatible means that it must have the same MSCP media
    ID code and same number of tracks, sectors, and cylinders as
    a drive already hardwired into vaxuba/uda.c.  These are the
    ones hardwired in:
        { MSCP_MKDRIVE2('R', 'A', 60), "ra60", ra60_sizes, 42, 4, 2382 },
        { MSCP_MKDRIVE2('R', 'A', 70), "ra70", ra70_sizes, 33, 11, 1507 },
        { MSCP_MKDRIVE2('R', 'A', 80), "ra80", ra80_sizes, 31, 14, 559 },
        { MSCP_MKDRIVE2('R', 'A', 81), "ra81", ra81_sizes, 51, 14, 1248 },
        { MSCP_MKDRIVE2('R', 'A', 82), "ra82", ra82_sizes, 57, 14, 1423 },
        { MSCP_MKDRIVE2('R', 'C', 25), "rc25-removable",
                                                rc25_sizes, 42, 4, 302 },
        { MSCP_MKDRIVE3('R', 'C', 'F', 25), "rc25-fixed",
                                                rc25_sizes, 42, 4, 302 },
        { MSCP_MKDRIVE2('R', 'D', 52), "rd52", rd52_sizes, 18, 7, 480 },
        { MSCP_MKDRIVE2('R', 'D', 53), "rd53", rd53_sizes, 18, 8, 963 },
        { MSCP_MKDRIVE2('R', 'X', 50), "rx50", rx50_sizes, 10, 1, 80 },
    Note that "rd54" is conspicuously missing, and I think the tabulated
    rd52/53 sizes are as appropriate on a RQDX2, *not* a RQDX3.
  Some other operating system to write the disk from
    (for example, VMS, NetBSD, BSD2.11 and a PDP-11/73/83/93 CPU, 
    RT-11 and any PDP-11 CPU, etc.)
  The tape distribution of 43reno_vax from the PUPS archive.  Specifically,
    you need these files:
      mdec/rdboot, from usr.tar
      mdec/bootra, from usr.tar 
      etc/etc.tahoe/disktab, from src.tar

Cooking directions:

  The miniroot wants to live in the swap ("b") partition of the drive.  So
  your first task is to find the starting block number of the swap
  partition from the extracted "disktab".  For example, for an
  RA81, the offset ("ob=") for an RA81 is 16422 blocks.  So copy
  the miniroot onto the target drive starting at block 16422
  (i.e. if you're under 2.11 BSD and you've partitioned the
  target drive, ra0, so that partition a covers the entire disk,
  do a "dd if=miniroot of=/dev/rra0a seek=16422 bs=512")

  In the "a" partition of the output drive you need a copy of "boot".  The
  miniroot already has a filesystem with this in it, so the lazy
  thing to do is to just plop another copy of the miniroot, starting
  at block 0 on the output disk (i.e. "dd if=miniroot of=/dev/rra0a")

  You need the secondary bootstrap in blocks 1-15 of the target
  disk.  Put this down with "dd if=bootra of=/dev/rra0a seek=1 bs=512"

  You need a block-0 boot block on the output disk.  For a Microvax,
  this is rdboot.  (I believe raboot is appropriate on a Unibus
  or BI-bus VAX).  Lay this down with "dd if=rdboot of=/dev/rra0a"

Now move the output disk to your Microvax II configuration, and boot:

>>> b dua0/r5:1


loading boot
ra0: unlabeled

: ra(0,0,1)vmunix
ra0: unlabeled
338756+108644+131004 start 0x238c
4.3 BSD Reno UNIX #1: Sat Jul 28 15:19:06 1998 PDT
  trent at
REAL MEM=16773120

und so weiter.

Now, one obvious improvement to this would be to lay down a fake
4.3-ish disk label at the start of the output disk as well.  This
way the reliance on a fully-geometry-compatible disk might be avoided.
I'll work on this in my Copious Free Time (TM).

 Tim Shoppa                        Email: shoppa at
 Trailing Edge Technology          WWW:
 7328 Bradley Blvd		   Voice: 301-767-5917
 Bethesda, MD, USA 20817           Fax:   301-767-5927

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